Nectarine tree, ‘Burnecttwentyfive’

ABSTRACT

A new and distinct variety of nectarine tree ( Prunus persica  sub species  nuciperisica ), denominated varietally as ‘Burnecttwentyfive’, and which produces an attractively colored firm-fleshed, acid, clingstone nectarine, which is mature for harvesting and shipment approximately July 14 to July 21 under ecological conditions prevailing in the San Joaquin Valley of central California.

Botanical designation: The present invention relates to a new, novel anddistinct variety of nectarine tree, Prunus persica (subspeciesnucipersica).

Varietal denomination: ‘Burnecttwentyfive.’

BACKGROUND OF THE NEW VARIETY

The present variety of nectarine tree resulted from an on-going programof fruit and nut tree breeding. The purpose of this program is toimprove the commercial quality of available deciduous fruit and nutvarieties, and rootstocks, by creating and releasing promisingselections of Prunus, Malus and Juglans species. To this end we makeboth controlled and hybrid cross pollinations each year in order toproduce seedling populations from which improved progenies are evaluatedand selected.

ORIGIN

The seedling ‘Burnecttwentyfive’ was originated by us from a populationof seedlings grown in our experimental orchards located near Fowler,Calif. The seedlings, grown on their own roots, were the result of acontrolled cross made in February of 2004 of a seedling of theyellow-fleshed clingstone nectarine tree “Burnectseven” (U.S. Plant Pat.No. 13,589) which was the seed parent, and an unnamed Burchell seedling,E25.071 nectarine tree which was the pollen parent. Within this seedlingpopulation one seedling, which is the present variety, exhibitedespecially desirable characteristics, and was designated as ‘N8.068’.This seedling was marked for subsequent observation. After the 2006fruiting season the new variety of nectarine tree was selected foradvanced evaluation and repropagation.

ASEXUAL REPRODUCTION

Asexual reproduction of the new and distinct variety of nectarine treewas accomplished by budding the new nectarine tree to ‘Nemared’Rootstock (USDA, non-patented). This was performed by us in ourexperimental orchard which is located near Fowler, Calif. Subsequentevaluations have shown those asexual reproductions run true to theoriginal tree. All characteristics of the original tree, and its fruit,were established, and appear to be transmitted through succeedingasexual propagations.

SUMMARY OF THE VARIETY

‘Burnecttwentyfive’ is a new and distinct variety of nectarine tree,which is considered of large size, and which has vigorous growth. Thisnew nectarine tree variety is also a regular and productive bearer ofrelatively large, firm, acidic, yellow fleshed, melting, clingstonefruit which have good flavor and eating quality. The tree of the presentvariety displays a medium chilling requirement of approximately 650hours or more. Still further, the present tree also produces relativelyuniformly sized fruit throughout the tree. Additionally, the fruitproduced by the present tree has a very high degree of red skincoloration, a firm, yet melting flesh and appears to have good handlingand shipping qualities. The ‘Burnecttwentyfive’ Nectarine tree bearsfruit which are ripe for commercial harvesting and shipment onapproximately July 14 to July 21 under the ecological conditionsprevailing in the San Joaquin Valley of central California. In relativecomparison to the seed parent tree (‘Burnectseven’ U.S. Plant Pat. No.13,589), the ‘Burnecttwentyfive’ Nectarine tree produces a nectarinewhich exhibits 20-40% more external red blush coloration than the seedparent. In relative comparison to the pollen parent tree E25.071,(unpatented) the ‘Burnecttwentyfive’ nectarine ripens approximately 7-10days earlier. In addition, the present new nectarine tree produces fruitapproximately 3-7 millimeters larger and requires approximately 150 lesschill units than the nectarine tree ‘Summer Fire’ (U.S. Pat. No. 7,506),which is the most similar commercial variety in ripening date known tothe breeders at this time. The lower chilling requirement of thepresent, new variety allows it to produce more flower buds than thenectarine tree ‘Summer Fire’ (U.S. Pat. No. 7,506), and subsequently the‘Burnecttwentyfive’ tree has exhibited the potential to produce largercrops.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawing, which is provided, is a color photograph ofthe new variety of nectarine tree. The photograph depicts two wholemature fruit, and one mature fruit which is dissected substantially inthe equatorial plane, and which is seen from the apical perspective.This photograph also reveals the flesh and the stone characteristicsthereof. The external coloration of the fruit, as shown, is sufficientlymatured for harvesting and shipment. Additionally, the photographdisplays a sample vegetative shoot bearing typical leaves; and a typicalstone; with the flesh removed.

The colors in the photograph are as nearly true as is reasonablypossible in a color representation of this type. Due to chemicaldevelopment, processing, and printing, the leaves and fruit depicted inthese photographs may or may not be accurate when compared to the actualspecimen. For this reason, future color references should be made to thecolor plates (Royal Horticultural Society Fourth Edition, 2001) and thedescriptions provided, hereinafter.

NOT A COMMERCIAL WARRANTY

The following detailed description has been prepared to solely complywith the provisions of 35 U.S.C. §112, and does not constitute acommercial warranty, (either expressed or implied), that the presentvariety will in the future display all the botanical, pomological orother characteristics as set forth, hereinafter. Therefore, thisdisclosure may not be relied upon to support any future legal claimsincluding, but not limited to, breach of warranty of merchantability, orfitness for any particular purpose, or non-infringement which isdirected, in whole, or in part, to the present variety.

DETAILED DESCRIPTION

Referring more specifically to the pomological details of this new anddistinct variety of nectarine tree, the following has been observedduring the sixth fruiting season under the ecological conditionsprevailing at orchards located near the town of Fowler, county ofFresno, state of Calif. All major color code designations are byreference to The R.H.S. Color Chart (Fourth Edition, 2001.) provided byThe Royal Horticultural Society of Great Britain. Common color names arealso occasionally used.

TREE

-   -   -   Size.—Generally — Considered medium-large as compared to            other common commercial nectarine cultivars ripening in the            same season of maturity. The tree of the present variety was            pruned to a height of approximately 300.0 cm to about 310.0            cm at maturity. The average spread of the new tree is            approximately 4.7 meters when measured during the fifth year            of growth.        -   Vigor.—Considered moderately vigorous. The present variety            grew from about 150.0 cm to 155.0 cm in height during the            first growing season. The new nectarine tree variety was            pruned to a height of approximately 140.0 cm during the            first dormant season, and primary scaffolds were then            selected for the desired tree structure.        -   Productivity.—Productive. The fruit set varies from 1.5 to            several times more than the desired crop load. The fruit set            is spaced by thinning to develop the remaining fruit into            the desired market-sized fruit. The number of the fruit set            varies with the prevailing climatic conditions, and the            current cultural practices employed during the bloom period.            Therefore, this characteristic is not distinctive of this            new variety.        -   Bearer.—Regular. Fruit set has been heavy, and significant            thinning was necessary during the past 5 growing seasons.        -   Form.—Upright, and pruned into a vase shape.        -   Density.—Considered medium dense. It has been discovered            that pruning the branches from the center of the tree to            obtain a resulting vase shape allows for proper air movement            in the tree, and appropriate amounts of sunlight to enhance            fruit color and renewal of fruiting wood throughout the            entire tree.        -   Hardiness.—The present tree was grown and evaluated in USDA            Hardiness Zone 9. The winter chilling requirements of the            new tree are approximately 650 hours at a temperature below            7.0 degrees C. The present variety appears to be hardy under            typical Central San Joaquin Valley climatic conditions.

TRUNK

-   -   -   Diameter.—Approximately 21.0 cm in diameter when measured at            a distance of approximately 15.24 cm above the soil level,            on trees which are six years old.        -   Bark texture.—Considered moderately rough, with numerous            folds of papery scarfskin being present.        -   Lenticels.—Numerous flat, oval lenticels are present. The            lenticels range in size from approximately 4.0 to about 8.0            millimeters in width; and from about 1.0 to about 2.0            millimeters in height. It should be noted that as the bark            of the trees mature, the lenticels become less apparent and            also less abundant.        -   Lenticel color.—Considered an Orange-Brown, (RHS            Greyed-Orange Group 166 D).        -   Bark coloration.—Variable, but it is generally considered to            be Grey-Brown, (RHS Greyed-Orange Group 177 A).

BRANCHES

-   -   -   Size.—Considered medium-large for the variety.        -   Diameter.—Average as compared to other nectarine tree            varieties. The branches have a diameter of about 12.0            centimeters when measured on trees which are six years old.        -   Surface texture.—Average, and appearing furrowed on wood            which is several years old.        -   Crotch angles.—Primary branches are considered variable            between about 45 to about 54 degrees from the horizontal            axis. This particular characteristic is not considered            distinctive of the present variety, however.        -   Current season shoots.—Surface texture — Substantially            glabrous.        -   Internode length.—Approximately 1.9 to about 2.4 cm. This            tree characteristic is highly dependent upon plant vigor            influenced by nutrition, soil quality, pruning and tree care            and therefore is not particularly distinctive of the new            variety.        -   Color of mature branches.—Medium-brown, (RHS Greyed-Orange            177 C).        -   Current season shoots.—Color — yellow green, (RHS            Yellow-Green Group N144 A). The color of the new shoot tips            is considered a bright and yellow green (RHS Yellow-Green            Group 151 D).

LEAVES

-   -   -   Size.—Considered medium-large for the species. Leaf            measurements have been taken from vigorous, upright,            current-season growth, at approximately mid-shoot.        -   Leaf length.—Approximately 135.0 to about 160.0 millimeters.        -   Leaf width.—Approximately 33.0 to about 39.0 millimeters.        -   Leaf base shape.—Slightly oblique relative to the            longitudinal axis of the leaf.        -   Leaf form.—Lancelolate.        -   Leaf tip form.—Acuminate.        -   Leaf color.—Upper Surface — Dark green, (approximately RHS            Green Group N134 B).        -   Leaf texture.—Glabrous.        -   Leaf color.—Lower Surface — Medium green, (RHS Green Group            143 A).        -   Leaf venation.—Pinnately veined.        -   Mid-vein.—Color. — Light yellow green, (RHS Yellow-Green            Group 150 C).        -   Leaf margins.—Generally — Slightly undulating. Form. —            Considered crenate, occasionally doubly crenate. Uniformity.            — Considered generally uniform.        -   Leaf petioles.—Size. — Considered medium long. Length. —            About 7.0 to about 10.0 mm. Diameter. — About 2.0 mm. Color.            — Pale green, (RHS Yellow-Green Group 144 B).        -   Leaf glands.—Size. — Considered generally small. About 1.0            mm in height and about 1.0 mm in width. Number. — Generally            one per side, occasionally two per side may be found. Rarely            glands are absent. Type. — Globose. Color. — Orange brown,            (RHS Green Group 137 B). The glands as described herein are            described as they would appear during mid-season, but before            advancing senescence.        -   Leaf stipules.—Size. — Medium for the variety. Number. —            Typically 2 per leaf bud, and up to 6 per shoot tip. Form. —            Lanceolate in form, and having a serrated margin. Color. —            Green, (RHS Green Group 141 A) when juvenile, but then            graduating to a brown color, (RHS Greyed-Red group 178 B)            with advancing senescence. The stipules are considered to be            early deciduous.

FLOWER

-   -   -   Flower buds.—Generally — The floral buds, depending upon the            stage of development, are approximately 8.0 millimeters            wide; and about 13.0 millimeters long; conic in form; and            slightly appressed relative to the bearing shoot.        -   Flower buds.—Color — The bud scales are reddish-brown,            (approximately RHS Greyed-Red Group 178 B). The buds are            considered hardy under typical central San Joaquin Valley            climatic conditions.        -   Hardiness.—No winter injury has been noted during the last            several years of evaluation in the central San Joaquin            Valley. The current variety has not been intentionally            subjected to drought or heat stress, and therefore this            information is not presently available.        -   Date the first bloom was observed.—Mar. 1, 2009.        -   Blooming time.—Considered early to mid-season in relative            comparison to other commercial nectarine cultivars grown in            the central San Joaquin Valley. Date of full bloom was first            observed on Mar. 9, 2009. The date of bloom varies slightly            with the prevailing climatic conditions, and cultural            practices which are employed.        -   Duration of the bloom.—Approximately 10 days. This            characteristic varies slightly with the prevailing climatic            conditions.        -   Flower type.—The variety is considered to have a showy-type            flower.        -   Flower size.—Flower diameter at full bloom is approximately            48.0 to about 56.0 millimeters.        -   Bloom quantity.—Considered abundant.        -   Flower bud frequency.—Normally 2 flower buds appear per            node. On occasion 1 bud per node may be observed. Stamen            count — On average, 35 stamens per flower appear.        -   Petal size.—Generally — Considered large for the species.            Length. — Approximately 21.0 to about 23.0 millimeters.            Width. — Approximately 17.0 to about 21.0 millimeters.        -   Petal form.—Rotund to slightly ovate.        -   Petal count.—Typically 5.        -   Petal texture.—Glabrous.        -   Petal color.—Somewhat variable from a light pink, (RHS            Red-Purple Group 65 B) to a medium pink, (RHS Red-Purple            Group N57 D).        -   Fragrance.—Slight.        -   Petal claw.—Form — The claw is considered cuneate in shape;            and has a medium size when compared to other varieties.            Length. — Approximately 11.0 to about 13.0 millimeters.            Width. — Approximately 9.0 to about 11.0 millimeters.        -   Petal margins.—Generally considered variable, from nearly            smooth, to moderately undulate.        -   Petal apex.—Generally — The petal apices appear entire with            a broad, shallow apical groove.        -   Flower pedicel.—Length. — Considered medium-long, and having            an average length of approximately 5.0 to about 6.0            millimeters. Diameter. — Considered average, approximately            2.0 to 3.0 millimeters. Color. — A pale green when bud            scales are removed, (RHS Greyed Green Group 195 A).        -   Floral nectaries.—Color. — An orange-brown, (RHS            Greyed-Orange Group N172 A).        -   Calyx.—Surface texture. — Generally glabrous. Color. — A            dull red, (approximately RHS Greyed-Red Group 178 B).        -   Sepals.—Surface texture. — The surface has a short, fine,            pubescent texture. Size. — Average; and ovate in form;            approximately 6.0 mm in length; and approximately 4.0 mm in            width. Color. — Upper Surface — A dark reddish purple,            (approximately RHS Greyed-Purple Group 183 C). Color — Lower            Surface — Grey-Brown (RHS N199B).        -   Anthers.—Generally. — Large in size. Color. — Red to            reddish-purple, (approximately RHS Orange-Red Group 32 A)            prior to dehistance.        -   Pollen production.—Pollen is abundant, and has a yellow            color, (approximately RHS Yellow Group 11 A).        -   Filaments.—Size. — Variable in length, approximately 14.0 to            about 17.0 millimeters in length. Color. — Considered a pale            pink, (RHS Red-Purple Group 63 C) at maturity.        -   Pistil.—Number. — Normally 1, very rarely 2. Generally. —            Average in size. Length. — Approximately 19.0 to about 21.0            millimeters including the ovary. Color. — Considered a very            pale green, (approximately RHS Yellow-Green Group 144 D).            Surface Texture. — The variety has a long glabrous pistil.

FRUIT

-   -   -   Maturity when described.—Firm ripe condition (shipping            ripe). Date of first picking. — Jul. 14, 2009 Date of last            picking. — Jul. 21, 2009. The date of harvest varies            slightly with climatic conditions.        -   Size.—Generally — Considered large, and uniform.        -   Average cheek diameter.—Approximately 68.0 to about 71.0            millimeters.        -   Average axial diameter.—Approximately 71.0 to about 73.0            millimeters.        -   Typical weight.—Approximately 255.0 grams. This            characteristic is highly dependent upon the prevailing            cultural practices, and therefore is not particularly            distinctive of this new variety.        -   Fruit form.—Generally — Rounded to slightly elongated            through its axis. The fruit is generally uniform in            symmetry.        -   Fruit suture.—Shallow, and extending from the mid-equatorial            region to the apex. No apparent callousing or stitching            exists along the suture line.        -   Suture.—Color — The background color appears to be a medium            yellow, (approximately RHS Yellow-Orange Group 16 B), with            some occasional red coloration, (approximately RHS Red Group            42 A).        -   Ventral surface.—Form — Often lobed in one hemisphere.        -   Apex.—Shape — Rounded.        -   Base.—Shape — Slightly retuse.        -   Stem cavity.—Shape — Rounded and relatively shallow. The            average depth of the stem cavity is about 1.0 cm. The            average width of the stem cavity is about 2.8 cm.        -   Fruit skin.—Thickness. — Considered medium in thickness; and            tenacious to the flesh. Texture. — Glabrous. Taste. — Slight            astringency is noted. Tendency to crack. — Cracking has not            been observed. Russeting has not been observed to date on            the oldest bearing trees.        -   Blush color.—The blush color is variable from a medium red,            (approximately RHS Orange-Red Group N34 B) to a dark red,            (approximately RHS Orange-Red Group N34 A). Blush color            ranges from approximately 70% to about 85% of the fruit            surface depending upon the sunlight exposure and prevailing            growing conditions.        -   Ground color.—Generally a light yellow, (approximately RHS            Yellow-Orange Group 15 B).        -   Fruit stem.—Moderate in length, approximately 6.0 to about            8.0 millimeters. Diameter. — Approximately 2.0 to about 3.0            millimeters. Color. — Light tan, (approximately RHS            Greyed-Orange Group 164 D).        -   Flesh.—Ripens. — Evenly. Texture. — Firm, and dense.            Considered melting. Fibers. — Few, small, and tender ones            are typically found. Aroma. — Slight. Eating Quality. —            Considered good. Flavor. — Considered sweet and acidic. The            flavor is considered pleasant. Juice. — Moderate. Brix. —            About 14.5 degrees. This characteristic varies slightly with            the number of fruit per tree; the prevailing cultural            practices; and the surrounding climatic conditions. Flesh            Color. — Yellow-orange, (approximately RHS Yellow-Orange            Group 16 A). As maturity increases a reddish pigmentation            (approximately RHS Red Group 46 B) develops. This            pigmentation can increase until a majority of the fruit            flesh develops a substantial degree of red coloration.

STONE

-   -   -   Type.—Clingstone.        -   Size.—Considered medium for the variety. The stone size            varies with the resulting crop load, and tree vigor, and is            therefore is not considered a distinguishing characteristic            of this new variety.        -   Length.—Average, about 27.0 to about 31.0 millimeters.        -   Width.—Average, about 22.0 to about 25.0 millimeters.        -   Diameter.—Average, about 17.0 to about 22.0 millimeters.        -   Form.—Obovoid.        -   Base.—The stone is slightly oblique relative to the stone's            vertical axis.        -   Apex.—Shape — The stone apex has a small acute tip.        -   Stone surface.—Surface Texture. — Substantial pitting is            evident, in general, from the base past the equatorial            plane. Grooving is usually observed along the pit margin            near the tip and on the ventral side. Ridges. — Texture —            The surface texture varies from sharp to rounded. Ventral            edge. — Width — Considered medium, and having a dimension of            approximately 3.0 to about 4.0 millimeters when measured at            mid-suture. Dorsal Edge. — Shape — Full, heavily grooved,            and having relatively smooth edges.        -   Stone color.—The color of the dry stone is a dull red            approximately (RHS Greyed-Red Group 181 B).        -   Tendency to split.—Rarely splits have been noted.        -   Kernel.—Generally — The kernel is considered mature at fruit            ripening dates. Form. — Considered ovoid. Kernel Size —            Approximately 8.0 to 11.0 mm in length; approximately 5.0 to            8.0 mm in width; and approximately 3.5 to 5.0 mm in            thickness. Pellicle. — Slightly pubescent. Color. —            Considered to be a pale brown (Greyed-Group Group 164 A).        -   Use.—The new variety ‘Burnecttwentyfive’ is considered to be            a Nectarine tree which matures early in the season, and            which produces fruit, which are considered firm,            attractively colored, and which are useful for both local            and long distance shipping.        -   Keeping quality.—Appears excellent. Fruit has stored well            for up to 25 days after harvest at 1.0 degree Celsius.        -   Shipping quality.—Good. The fruit of the new nectarine tree            variety showed minimal bruising of the flesh, or skin            damage, after being subjected to normal harvest and packing            procedures.        -   Resistance to insects and disease.—No particular            susceptibilities were noted. The present variety has not            been tested to expose or detect any susceptibilities or            resistances to any known plant and/or fruit diseases.

Although the new variety of nectarine tree possesses the describedcharacteristics when grown under the ecological conditions prevailingnear Fowler, Calif., in the central part of the San Joaquin Valley ofCalifornia, it should be understood that variations of the usualmagnitude and characteristics incident to changes in growing conditions,fertilization, pruning, pest control and horticultural management are tobe expected.

Having thus described and illustrated our new variety nectarine tree,what we claim is new and desire to secure by Plant Letters Patent is: 1.A new distinct variety of nectarine tree, substantially as illustratedand described, and which is characterized principally as to novelty byproducing an attractively colored, firm-fleshed, acid, clingstonenectarine which is mature for harvesting and shipment approximately July14 to July 21 under the ecological conditions prevailing in the SanJoaquin Valley of central California.